7-Chloro-1-ethyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid → Norfloxacin

Participants

Reaction Conditions

Reaction Steps

0.5 g (1.85 mmol) of 1-ethyl-6-fluoro-7-chloro-4-oxo1,4-dihydro-quinoline-3-carboxylic acid (II, R1 : ethyl; X: chloro) and 1.1 g (5.5 mmol) of 1-(t-butyldimethylsilyl) piperazine (R2 : hydrogen, R3 and R4 : methyl; R5 : t-butyl) are added to 5 ml of pyridine and then heated at 60° C. A solution of 1.73 g (5.5 mmol) of tetrabutylammonium fluoride trihydrate in 5 ml of pyridine is added dropwise to the reaction mixture. After completion of addition, the reaction mixture is heated at 80° C. for 2 hours and then distilled under reduced pressure (10 mmHg, 60° C.). The residue is added with water and then stirred to afford a crystal. After filtering and drying, 0.50 g of a solid product is obtained.

Provenance & Evidence